Efficacy of sequential use of superparamagnetic iron oxide and gadolinium in liver MR imaging

To evaluate the efficacy of combined (double contrast) use of superparamagnetic iron particles (SPIOs) and gadolinium (Gd) in liver MR imaging.

Unenhanced, Gd-enhanced, SPIO-enhanced, and both SPIO- and Gd-enhanced images were acquired at 1.5 T. Twenty patients with previously detected liver lesions were included. Fast SE-STIR, and breath-hold true FISP, fat-suppressed T1- and T2-weighted sequences were obtained with all techniques. Lesion count was assessed by consensus reading.

Collective evaluation of all MR sequences revealed 61 lesions in 16 patients; SPIO-enhanced MR detected lesions with a sensitivity of 95% (n=58). The sensitivity of unenhanced MR imaging was 90% (n=55). There was no statistical difference between SPIO-enhanced and unenhanced MR images. From single sequences, the greatest number of lesions was detected with the SPIO-enhanced fast SE-STIR sequence (n=56, sensitivity 92%). By using the fat-suppressed T1-weighted sequence, Gd-enhanced and both SPIO- and Gd-enhanced MR images demonstrated sensitivities of 77% (n=47) and 80% (n=49), respectively. Despite the combined use of both contrast media, this sequence was significantly less sensitive in lesion detection when compared to SPIO-enhanced imaging.

SPIO-enhanced MR imaging was the most sensitive method in lesion detection. The benefit of the combined use of SPIO and Gd was negligible.